It might be a smart idea to include what game you're asking about.

I'm guessing you're talking about Street Fighter, you should probably ask in the right place next time.

But to answer your question, you can't use Japanese.

nope, you cant change language to jap unlesss you have a jap version of SSF3D

Since you didn't specify what game you're questioning about, I will answer it as if it was a broad question or as if you are asking about all games. I will also assume that you have an American copy of the 3DS.

In most cases, the answer will be NO simply because you have the American copy of that game. To have it in a different language, you would need a 3DS from that country or region.

WARNING: Do not purchase a game from a different region. It will not function on your 3DS. You would need for ex: a Japanese 3DS to play the Japanese version of a game. It's a waste of money anyway because you'll compatibility issues with almost every software and everything is in Japanese!

I can't speak for every case but most games won't have a language setting- Nintendo published games. Third party games may. Nintendo publications will only have languages that are also within your "'System Settings".

Conclusion if it's a must:

Purchase a Japanese or the region's version of the 3DS and a Japanese or a region's copy of a game. Save money by purchasing it used and off of Amazon, eBay, or any other online trusted websites.

-You must know how to read the language's writing or have had experience with it.

--This concludes my answer--

-Answer written by using 3DS Internet Browser.

*Some things within this answer may be inaccurate or false. Message me through GameFaq if so.

-DerJohann, GameFaq